Acetylene black for batteries

Acetylene carbon black is a high-purity acetylene obtained through the decomposition of by-products from calcium carbide or naphtha (crude gasoline) pyrolysis, followed by purification. It is further processed into carbon black through continuous pyrolysis. After the reaction furnace is heated to a temperature above 800°C, which is the starting temperature for acetylene decomposition, acetylene is introduced to begin the thermal decomposition process. As it is an exothermic reaction, it can proceed automatically. To maintain stable quality, the reaction temperature should be kept around 1800°C. The furnace temperature can be controlled via the water-cooled jacket surrounding the external cylinder of the reaction furnace. Acetylene carbon black is used as an anode material in manganese dry batteries, in conjunction with manganese dioxide and electrolyte. Compared to furnace carbon black, it has more developed crystalline and secondary structures, resulting in superior conductivity and absorbency. Due to the low presence of heavy metals and other impurities, the self-discharge loss is minimal, and its storage performance is excellent. Acetylene black almost dominates the market and is expected to continue with the demand for dry batteries in the future.

Acetylene carbon black is a very fine black powder, with a relative density of 1.95 (by nitrogen displacement method). The apparent density is 0.2 to 0.3 g/cm³. The average particle size is 30 to 45 nm. The specific surface area is 55 to 70 m²/g. The iodine adsorption value is 60 to 80 gI₂/kg. Acetylene carbon black has a high purity, with carbon content greater than 99.5%, hydrogen content less than 0.1%, and oxygen content between 0.07% and 0.26%. The pH value is 5 to 7. It has a low resistivity, offering excellent conductivity, thermal conductivity, and resistance to static effects.